That 350w rating is pretty much meaningless. Look for the combined +5 and +3.3 numbers. Some name brand 300w will have higher numbers here than some generic 400w PS's (165w is the bare minimum, over 200w is better).

It's also a good idea to check how many amps your mobo wants on the +3.3 rail. Many newer mobo's want more than the 20A that was standard a while back. I believe you want one that outputs 28A with your ECS.

I got a Antec 350 watt ps. it works fine for my XP 2000...which btw is overclocked...i have 4 case fans and two optical drives and a hdd and fdd...all works flawlessly. the amp thing is correct...i bought this ps because it had more amps than the cheapo 400 watt ps...oh well 350 is perfect...good luck

Yeah the antec 350 is fine, I have an xp 2200, gf 4 4200, 2 hds 2 optical drives, and 6 fans on my 350 watt antec. I think I'm pushing it a little and should probably move up to 400 or 450, but I haven't experienced any problems with my computer so I'll probably stick with the 350 until I get 2 more serial ATA hard drives.